Crank assembly



Apri] 215 1953 G. F. KAROW 2,635,484

CRANK ASSEMBLY Filed Sept. 20, 1948 4 Sheets-Sheet l AUTOR/VE .5'

April 2l, 1953 G. F. KARow 2,635,484

CRANK ASSEMBLY Filed Sept. 20, 1948 4 Sheets-Sheet 2 72 2G a V ,as 2a @lg@ l l I3 Q Q a5 as az 2z 7| 70 Q 45 az JNVENTOR. @s0/Q65 /Weow pril 2l,1953 G. F. KAROW 2,635,484

CRANK ASSEMBLY Filed Sept. 20, 1948 4 Sheets-Sheet 3 INVENTOR. @5o/eef/mon/ BY April 21, 1953 G. F. KARow 2,635,484

CRANK ASSEMBLY Filed Sept. 20, 1948 4 Sheets-Sheet 4 ELL-TT; ll 97 IlilPatented pr. 21, 1953 UNITED lSTATES PATENT OFFICEv 2 Claims.

This invention relates generally to motion transmitting mechanism andrefers more particularly to improvements in mechanism for convertingsliding motion to rotary motion or vice versa.

One of the objects of this invention is to provide motion transmittingmechanism composed of a relatively few simple parts capable of beinginexpensively manufactured, assembled and installed in a compact case.

Another object of this invention is to provide motion transmittingmechanism having a shaft 'assembly provided with axially spaced alignedparts journalled on the case and connected by a shaft section inclinedwith respect to the aligned axes of the shaft parts.

' Still another object of this invention is to connect the inclinedshaft section to an element supported inthe case for sliding movement inopposite directions along a path extending generally parallel to thealigned axis of the shafts by a member journalled on the inclined shaftpart and having a radially outwardly extending portion connected to theelement.

Still another object of this invention is to provide a shaft assemblycomprising axially aligned end and intermediate shaft parts spacedaxially 'from one another and connected together by inclined shaftsections, which in turn, are respectively connected to reciprocableelements for operating the latter upon rotation of the shaft as- .t

bustion engines of the opposed piston type wherein the opposed pistonsare respectively connected 'to 'the inclined shaft sections, as itenables one piston to be operated in advance of the other.

' A still further object of this invention is to provide a bearing forthe intermediate shaft part, composed of separable sections designed toenable installing the shaft assembly endwise through one 'end of thecase.

` Another feature of this invention is to counterlbalance the weight andforces of the assembly 'noted above with weights positioned to affordboth static and dynamic balance. .Y

- A still further obj ect of this invention is to proset forth aboveembodying relatively simple means for supplying lubricant to practicallyall friction surfaces and for spraying lubricant on the slidable elementfor cooling the latter.

In addition to the foregoing, this invention contemplates motiontransmitting mechanism of the general type set forth adaptable tointernal combustion engines of the multicylinder barrel type. l

The foregoing as well as other objects will b made more apparent as thisdescription pro,- ceeds, especially when considered in connection withthe accompanying drawings, wherein:

Figure 1 isv a longitudinal sectional view through an internalcombustion engine embodying motion transferring mechanism constructed inaccordance with this invention;

Figures 2, 3, 4 and 5 are sectional views taken respectively on thelines 2 2, 3--3, 4--4 and 5-5 of Figure 1;

Figure 6 is a sectional view showing the connection between one of thepistons and the associated operating arm;

Figures 7 and 8 are cross sectional views of a modified shaft assemblywherein one inclined section is angularly offset relative to the other;I'

Figure 9 is a fragmentary sectional view showing a further embodiment ofthe invention;

Figure 10 is a fragmentary sectional view showing still another modifiedshaft assembly; and

Figure 11 is a sectional view on the line I I-I`I of Figure 10.

The motion transferring mechanism embodying the features of thisinvention is shown, for the purpose of illustration, as applied to aninternal combustion engine of the opposed piston barrel type. However,it will be apparent from the following description that the mechanismmay be advantageously used in practically any installation where it isdesired to translate reciprocating motion to rotary motion or viceversa,

Referring now more in detail to the drawings, it will be noted that thenumeral I designates a case comprising an annular intermediate sectionII and end sections or walls I2 removablyv secured to opposite ends ofthe intermediate section by studs. Formed in the intermediate section IIadjacent the periphery of the latter is "a plurality of cylinders I3spaced equal distances from each other circumferentially of the sectionII and having jacketed walls I4 for the circulation of a suitablecooling medium. Each cylinder isof sumcient length to slidably supporttwo pistons I5 and I6 having sealing rings I'I of the :vide motiontransmittingmechanismlof'the type V expansion Htype.supported in annularr0QV formed in the head portions. In the present instance wear resistingsleeves I8 are secured in the outer end portions of each cylinder forengagement by the pistons and contracting sealing rings I9 are carriedby the sleeves for contact with the skirt portions of the pistons. Theexpansion rings on the pistons and the contracting rings on the sleevescooperate to prevent the escape of gases past the pistons from thechambers in the cylinders between opposed pairs of pistons. Also theserings prevent the escape of lubricant past the pistons into the chambersin the cylinders between opposed pairs of pistons, It will also be notedthat each cylinder is formed with axially spaced intake and exhaustVports 20 and 2| positioned to be uncovered by the pistons when thelatter are in their outermost positions shown at the bottom of Figure 1of the drawings. In the outermost positions of the pistons the rings I1,of course, assume positions beyond the Vports but at the inner sides ofthe rings I9 on the sleeves I8, so that the rings on the pistons andsleeves do not interfere with one another during normal operation of thepistons.

As shown in Figures 1 and 4 of the drawings, the inner walls of thecylinders I3 are formed with radially inwardly extending lugs 22intermediate the ends thereof to which a bearing 23 is removably securedby studs 24. In detail, the bearing 23 is formed of two complementaryhalves 25 secured together by fastener elements 26 and having a lining21 of bearing metal. Each bearing half is formed with outwardlyextending ears 28 positioned to register with the lugs 22 and attachableto the latter by the studs 2'4.

Rotatably supported within the case by the bearing 23 is a shaftassembly 29 having an intermediate portion 30 and having parts 3l atopposite ends axially aligned with the intermediate portion. Theintermediate portion 30 is journalled in the bearing 23 and is formedwith an annular groove 32 for receiving the bearing 23. The shaftassembly and associated parts to be presently described are staticallyand dynamically balanced by counterweights 33 positioned on theintermediate portion of the shaft assembly at opposite sides of thebearing 23. lIhe Weights 33 are shown in the drawings as formed integralwith the intermediate shaft section 30, although it will be understoodthat these weights may be formed separately and removably secured to theshaft if desired.

During assembly the shaft 29 is inserted into the Vcase YI through oneend thereof prior to securing the end walls |2 in place. Theintermediateportion 30 of the shaft is positioned'in onehalf of thebearing 23, and the complementary half of the bearing is then secured inplace by the fastener elements 26. After the shaft assembly is installedwithin the case I0, the end Walls I2 may be secured in place at oppositeends of the case to complete the assembly,

The oppositeend parts 3| of the shaft assembly are respectivelyjournalled on the end walls I2 of the case IIJ by roller bearings34,'respectively secured within recesses 35 formed in the end Walls I2.The inner ends of the shaft lparts 3| are provided with enlargements 36having bores 38 formed with their axes-extending in the generaldirection of the common laxis of the vshaft parts 3|, but inclined withrespect `to the latter.

The shafts 3| arerespectively connected to the 'intermediate shaftportion v30 by shaft vsections or Aparts 39 formed integral with theshaft -por- -tion 30 and having the axes thereof respectively alignedwith the axes of `the-bores 38 in .theenzu largements 38. In fact theouter ends of the shaft sections 39 respectively extend into the bores38, and are splined to engage corresponding splines formed in the innersurfaces of the bores 38. The end portions of the shaft sections 39engaging in the bores 38 are reduced in diameter to form annularshoulders 4I) on the shaft sections for abutting engagement with theshafts 3| at the inner ends of the bores 38. This arrangementestablishes a xed relationship between the shaft sections 39 and shaftparts 3| during assembly, and assures alignment of the shaft mainbearings.

The outer ends of the shaft sections 39 are secured in the respectivebores 38 by clamps 4| formed by slitting the walls of the bores at theouter ends of the latter as at 42 in Figure 3 of the drawings. It willalso be noted from Figure 3 of the drawings that the enlargements 36 ofthe shafts 3| are formed with outwardly projecting ears 43 at oppositesides of the slot and studs 44 are provided for drawing the slitportions together to clamp the adjacent ends of the shaft sections 39 inthe respective bores 38.

For reasons to be more fully hereinafter described, the shaft sections39 are axially bored to form passages 45 enlarged at the outer ends ofthe shaft sections and closed by thrust screws 48 respectively threadedinto the enlarged outer ends of the passages 45. The shafts 3| arerecessed as at 41 to provide clearance for the screws 45, and in theinterests of compactness, the recesses are formed in the shafts 3| inthe planes of the bearings 36. The recesses v41 are normally filled byblocks 48 removably secured in the respective recesses by fastenerelements 49. As shown in Figure 5 of the drawings, the outer surfaces ofthe filler blocks 48 form continuations of the cylindrical surfaces ofthe shafts 3| and provide a continuous bearing surface contact with thebearings 34. The blocks 48 enable reducing the lengths of the respectiveshaft parts 3| to a minimum, and this is important as it enablescorrespondingly reducing the overall length of the unit. Attention isalso called to the fact at this time that end thrusts imparted to theshaft assembly are taken by the screws 46 and clamps 4|.

The shaft sections 38 are respectively connected to the pistons I5 andI6 by wobble plate assemblies 50 and 5|. Each assembly comprises anannular portion 52 rotatably supported on the adjacent shaft section 39intermediate the ends thereof and having arms 53 extending radiallyoutwardly from the annular portion. Adjacent arms 53 are connectedtogether by braces 54 and the number of arms corresponds to the numberof cylinders. Projecting laterally outwardly from opposite sides of thearms 53 of each assembly are hub sections 55 having provision at theouter ends for supporting ball bearings 56. The bearings 56 at the innersides of the assemblies are mounted on .the shaft sections 39 adjacentshoulders at opposite ends of the intermediate shaft part 30 and thebearings at .the outer sides of the assemblies are respectively mountedon the shafts 3| in concentric relation to the axes Aof the bores 38. Aspacing Washer 51 is located between the axially outer side of eachendbearing 56 and the adjacent side of the associated shaft 3| toprovide a running clearance for these bearings. The axial distancebetween the bearings 56 of each wobble plate" assembly assuresanexceptionally stable construction capable of withstanding substantialiloads '.without The outer endsA of the arms 53 project intotherespective cylinders through open ended slots S formed in opposite endsof the cylinders. The construction is such as to enable the shaftassembly 29 including the ybearings and parts 50 and 5l to be installedas a unit within the case I0. The arms 53 are connected ktotheirrespective pistons by couplings 60 securedto the skirt portions of thepistons. Each coupling comprises a bushing 6I positioned to slidablyreceive the end of the adjacent arm 53, and having trunnions 162projecting outwardly. from diametrically opposite sides thereof. Thetrunnions 62 of each coupling are journalled in bearings 63 carried bythe skirt of the adjacent piston. One-half of the bearings are formed onthe piston skirt and the other half are formed by caps 64 secured to thepiston skirt at opposite sides of the bushing 6I by studs 65. Thus thecouplings 60 permit a combined sliding and pivotal or swinging movementof the arms 53 relative to the pistons connected to the arms.

It follows from the foregoing that when the motion transferringmechanism described is applied to a barrel type internal combustionengine of the type illustrated, sliding movement of the pistons inopposite directions in their respective cylinders imparts a rotativemovement to the shaft assembly 29. On the other hand, if the motiontransferring mechanism previously described is applied to a pump, forexample, rotation of the shaft assembly 29 by some type of power meansimparts a reciprocable movement to the pistons;

It has previously been stated that the shaft sections 39 are formed withpassages 45 therethrough. As shown in Figure 1 of the drawings, theadjacent ends of the passages 45 communicate with an annular recess 'l0in the bearing 23 through a transversely extending passage H in theintermediate shaft part 30. The annular recess l0 communicates with asupply of lubricant under the pressure of a pump (not shown) through aconnection 12,' with the result that the bearing 23 is adequatelylubricated. It will further be noted'from Figure l1 of the drawings thatthe passage 'H is also connected tothe inner ends of passages 'H'having'the outer ends communieating with the axially inner set of ballbearings 56 through restricted ports 7l. The construction is such thatlubricant is, in effect, supplied to the bearings 56.

The outer ends of the passages 55 respectively communicate with theinner ends of reduced pas- 'sages 13 formed in Vtheplugs 46,` and theouter ends of the passages 13 are directed to spray lubricant on thebearings 34. 'Thus the bearings 23, 34 and inner set of bearings 56 arecontinuously lubricated during operation of the engine or motiontransferring mechanism. In this connection attention is called to thelubricant seals 'le carried by the end walls I2 of the case andrespectively frictionally contacting the shafts 3| to prevent the escapeof lubricant out of the case along the shafts 3|. The excess lubricantdrops to the bottom oi the case, and

is drained or conducted backto the reservoir through ports 15 in thecase. Y

It will further be noted from Figure 1 of the drawings that each arm isaxially drilled or otherwise fashioned with a passage 'l1 having theinner end communicating with an annular recess 18 in the annular portion52, and `having the outer ends extending through the corresponding endsof the arms. Suitable plugs 18' are provided for closing the outer endsof the passages Tl. Lubricant from the passages 11 is supplied to boththe inner and outer sets of bearings 56 through ports 11 formed in theannular portions 52 in circumferential spaced relationship. Inasmuch asthe inner set of bearings 55 is supplied with lubricant bythe passagesll', the inner ports ll may be omitted, if desired. Lubricant from thepassages 45 is supplied to the recesses 'I8 in the annular portions 52through passages 19 extending transversely through the shaft sections39.Y l Y Referring again to Figure 1 of the drawings,

Vit Will be seen that the outer ends of the passages 'l are connected totransverse passages 19 formed in the outer end portions of the .arms 53in` positions to lubricate the bushings 5i. Also longitudinal recesses89 are formed in the outer ends of the arms 53 at the sides of thelatter facing the piston heads, and these recesses communicate with thepassages 19'Yto receive lubricant from the latter. This lubricant isintroduced into the associated skirt portions of the pistons against theheads thereof through passages 8l formed in the sides of the bushingsadjacent the recesses 80. The length of the recesses 8i) is such thatthe passages 8l are in constant communication with the recesses 89throughout the reciprocable movement ofthe arms 53 in the respectivebushings 6l. Thus the pistons are continually sprayed Awith lubricantduring operation of the mechanism and are prevented from overheating. Y

Referring now to Figure 6 of the drawingsit Will be noted that thetransverse passages 19 also supply lubricant to arcuate grooves 89'formed in the arms 53 opposite thel grooves 89. The arcuate groovescommunicate with the bearings 63 for the trunnions 62 through passages8| formed in the couplings. Thus the vbearings 63 are adequatelysupplied with lubricant during operation of the mechanism.

When the above generalA constructionv is employed in connection withtwo-cycle internal combustion engines of the type illustrated in Figure1 of the drawings, it is possible to obtain some degree of superchargingby angularly offsetting the plane through the axis of one shaft section39 and including the axis of the aligned shafts 39 and 3i with respectto the corresponding plane of the other inclined shaft section. In orderto secure some degree of supercharging, the above Vplanes of the shaftrsections 39.. are angularly `offset in they manner shown in Figures 7and 8 of the drawings to retard the stroke of the intake portcontrolling piston with respect to the stroke of the piston controllingexhaust ports. Thus the exhaust ports are opened slightly in advance ofthe intake ports, and are closed some time in advance of the intakeports. The angular relationship between the above planes of the shaftsections 39, or in other words, the timing between the operation of theopposed pistons may be varied within limits to afford differentoperating characteristics. It may be pointed out that opening of theexhaust ports slightly 'in advance of the intake ports reduces theexhaust pressures before the intake port opens and thereby minimizes anytendency for the incom- -ing fuel mixture to blow back when the intakeports are opened.

The embodiment of the invention shown in Figure 9 of the drawingsdiffers from the above described construction in that the outer ends ofthe shaft sections 39 are tapered and the bores '.38 inthe adjacentshafts 3| are correspondingly threadedon the outer ends of the shaftsections for securely holding the shafts 3| and sections 39- againstrelative axial movement.

The embodiment of the invention shown in Figures 10 and 11 of thedrawings is similar to the first described form with few exceptions.Before describing these exceptions, it is pointed out that only one endof the shaft assembly is shown in Figure 10 and that the opposite end ispreferably identical in construction. In detail the roller bearings 34are omitted, and plain bearings 90 are substituted therefor. Also theflanges at the outer ends of the plugs 46 are omitted and thrust collars9| are respectively threaded on the outer ends of the plugs 92 inpositions to provide abutments for the outer ends of the shaft. Inaddition the arrangement for supplying lubricant to both the plainbearings 90 and ball bearings 56 is somewhat different. As shownpassages 92 and 93 arey drilled in the enlargements 36 of the shafts 3|.The inner ends of these passages communicate with one another and theouter ends of the passages are respectively located at the plainbearings 90 and ball bearings 56. Suitable plugs 94 are provided at theouter ends f the passages and restricted openings are formed in theplugs for supplying lubricant to the bearings. In the present Vinstancelubricant is supplied to the passages 93 by passages 95 which connectthe passages 93 to the passages 45 in the shaft sections 39. However, ifdesired, lubricant may be supplied directly from the. source into thepassages 92 by providing separate lubricant connections at the mainbearings 90, as shown at 10 and 12 of the center main bearing.

Upon reference to Figure 10 of the drawings, it will be noted that theshaft section 3|' has a radially outwardly extending flange 96 at theouter end which prohibits sleeving the bearing 90 over the shaft.Accordingly the bearing 90 is formed of two sections 91 and 98. Thesesections are clamped together on the shaft 3| by studs 99 and arepositioned within a central opening |00 in the adjacent end of thehousing. The bearing sections are also formed with radially outwardlyprojecting fianges |0| and the latter vare clamped to the inner side ofthe housing by studs |02. It will be noted from Figure 10 of thedrawings that the outer surface of the sectional bearing is tapered andthe adjacent surface of the housing is also tapered so that tighteningof the studs |02 supplements the action of the studs 89 to clamp thebearing sections in position on the shaft section 3|.

What I claim as my invention is:

1. Motion transmitting mechanism comprising a case having means forsupporting a bearing, a shaft rotatably supported in the bearing andhaving an enlargement at one side of the bearing, said enlargementhaving a bore extending in the general direction of the shaft and havingthe axis of the bore inclined with respect to the axis of the shaft, atubular shaft having one end extending into the bore and having said endclosed by a removable thrust element, said first named shaft beingrecessed in the plane of the bearing to provide clearance for the thrustelement, and an insert removably secured to the shaft at the recess andhaving the outer surface forming a continuation of the bearing engagingsurface on said first shaft.

2. Motion transmitting mechanism comprising a case having an end wall, ashaft supported on the end wall for rotation having a tubular partangularly disposed with respect to the axis of the shaft, said shafthaving a recess therein at the outer end of the tubular part, a secondshaft aligned with the axis of the tubular part and having the outer endextending into said part, means for securing the outer end of the secondshaft t0 the first shaft, a shoulder on the second shaft engageable withthe inner end of the tubular part, a thrust element carried by thesecond shaft and having a portion located within the recess inengagement with the outer end of the tubular part, a filler blocksecured within the recess at the outer side of the thrust element andcooperating with the remainder of the first shaft to provide acylindrical surface, and a bearing for the first shaft engageable withsaid cylindrical surface.

GEORGE F. KAROW.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,204,892 Macomber Nov. 14, 1916 1,316,679 Brackett Sept. 23,1919 1,392,389 Anderson Oct. 4, 1921 1,543,113 Lleo et al June 23, 19251,732,659 Redrup Oct. 22, 1929 1,799,167 Hulsebos Apr. 7, 1931 1,997,279Chilton Apr. 9, 1935 2,081,157 Swenson May 25, 1937 21,104,391 RedrupJan. 4, 1988 2,182,213 Redrup Dec. 5, 1939 2,215,086 Schwager Sept. 17,1940 2,247,527 Stinnes July 1, 1941

